Basic Physics Questions and Answers

If A B and C are vectors having a unit magnitude 4 If A B C 0 then A B B C C A will be 1 1 2 3 3 3 2 1 3 4 zero 2 ABC Son A B C 0 1 1 2 3 2

6 94 Particles of mass m and energy E move from the left to the potential barrier shown in Fig 6 3 Find a the reflection coefficient R of the barrier for E Uoi b the effective penetration depth of the particles into the region x 0 for E Uo i e the distance from the barrier boundary to the point at which the probability of finding a particle decreases e fold E UA H U

24 04 An object is at a depth H below The surface of le liquid of refractive index What is its apparent depth when the angle of vision at surface is 0 from vertical 3 I D a 3 8 1 pelos a sine 3 H 2 lose 7 C cos HE LONE

The current and voltage function in an AC circuit are I 100 sin100t mA V 100 sin 100t 10 3 volt the power dissipated in the circuit is 1 10 W 2 2 5 W 3 5 W 4 5 kW

A 2uF capacitor is charged to 100 V After disconnecting the battery a 20 mH coil is then connected across the charged capacitor The capacitor discharges through the inductor and the current in the circuit is oscillatory Maximum current in the circuit assuming zero resistance of the coil is 1 0 5 A 2 0 75 A 3 1 A 4 1 5 A 31

TARGET PRE MEDICAL 20 A 10 kg mass is resting on a horizontal surface and horizontal force of 80 N is applied If 0 2 the ratio of acceleration without and with friction is g 10 m s CAREER INSTITUTE KOTA RAJASTHAN 1 2 4 2

9 Two charges q and 4q are 1 m apart What are the location magnitude and sign of a third cha placed so that the entire system is at equilibrium NCERT 10 Two similarly and equally charged identical metal spheres A and B repel each other with a for

Box k A semi circular current carrying wire having radius R is placed in x y plane 2R with its centre at origin O There is non uniform magnetic field B here Bo is ve constant is existing in the region The magnetic force acting on semi circular wire will be along A C x axis PA y axis La som en adi voi eixe n adl B D y axis x axis R 0 0 Z R 0 0 X

A 4 R 4 R A long straight metal rod has a very long hole of radius a drilled parallel to the rod axis as shown in the figure If the rod carries a current i find the value of magnetic induction on the axis of the hole where OC c Hoic A b a Hoic B 2 b a C Hoi b a 2 c D Moic 2 a b

The sun orbits the centre of the galaxy Milky Way in almost circular path of radius R in a period T and the earth also orbits the sun in an almost circular path of radius r in a period t Assume whole mass of the galaxy concentrated at its centre and find an expression for the ratio of the mass of the galaxy to that of the sun a R G T B L R t 3 T BA r a R TY

ET Part I cing an gth of en the Last Leap for NEET Part I A ray of light is incident on a prism of angle A and refractive index u will not emerge out of prism for any angle of incidence if 1 sin 3 A N 2 1 sin A 2 cos A 4 1 sin A Ray Optics and 27 A small air bubble is prose of a glass sphere Size of the outside is of 1 Same size 2 Bigger 3 Smaller 4 May be smal distance of c ho maximum angle of acceptance 28 An object is at concave mirro

33 In the given arrangement string and pulleys are massless and mass of wedge M following statements are correct Neglect friction every where Wedge m M 16g A Downward acceleration of m with respect to wedge is 21 4g B Acceleration of wedge with respect to ground is 21 C Acceleration of mass m with respect to ground is 4g 17 5g D Acceleration of wedge with respect to ground is 21 4m then which of th

For given figure ma is 30 kg mB mc 5 kg respectively All contact surfaces are smooth g 10 m s2 Select the correct statements B Tension in string is 30N Contact force between R and C is 20 N A Acceleration of block A B and C arc 1 m s 4 m s and 5 m s2 respectively O Contact force between B Ground is 350 N

QR P S T XW this equation is V dimentionally correct where all the letters represent physical quantities then choose the incorrect statement s none is dimensionless If

If one surface of a biconvex lens is silvered then it behave as 1 A concave mirror of focal length 2 A concave mirror of focal length 3 A convex mirror of focal length R 4 2 R 2 R 4 2 4 A concave mirror of focal length R 2 2

Displacement of a particle is given as x A e kt sin Bt C which of the following is are correct B k is dimensionless B k may be a meaningful term Dimension of A CI A k is LT 2

Five charges of equal magnitude placed at corners of a regular pentagon of side a The force on qo which is placed at centroid O is Q 1 S zero E Qo 2kQq A 9 Question Type Single Correct Type O D B Q

A source of emf V sin ot is connected in series with an inductor L capacitor C and resistor R Calculate the impedance and resonant frequency of the circuit Also write an application of the resonant

7 A small air bubble is present exactly at the cent of a glass sphere Size of the image as seen fr outside is of 1 Same size 2 Bigger 3 Smaller 4 May be smaller or bigger depending

ALLEN CAREER INSTITUTE HOTA CAMASTHAND TARGET PRE MEDI Three equal weights A B and C of mass 2kg are hanging on a string passing over a fixed pu which is frictionless as shown in figure The tension in the string connecting weight B and g 9 8m s nearly 1 Zero to A B 2 13 N

4 Change will depend upon velocity A body of mass 2 kg is hung on a Spring baland mounted vertically in a lift moves up with acceleration equal to the acceleration due to gravity the reading on the spring balance will be 1 2 kg 2 2 g kg 3 4xg kg 4 4 kg

A conducting loop carrying a current I is placed in a uniform magnetic field as shown The loop will have a tendency to y Contract BO 1 2 Expand 3 Move toward ve x axis 4 Move toward ve x axis X

Initially system is in equilibrium If the spring between A B is cut then just after cutting Assume all springs are massless and identical Acceleration of block A is 2g upwards Acceleration of block A is 4g upwards Acceleration of block B is 4g 3 downwards Acceleration of block B is 4g downwards 000000000000 A 2m B3m m

If resultant of two vectors A and B is perpendicular B If A 4 3 B 6 then 75 Angle between A and B is radian Magnitude of resultant is 2 3 B A B 0 Angle between A B and is acute angle A

If resultant of two vectors A and B is perpendicular to g If 4 3 B 6 then 0 7 Angle between A and B is radian Magnitude of resultant is 2 3 B A B Angle between A B and A is acute angle 0

INSTRUCTIONS For questions 22 through 27 please refer to the following circul R1 www 2 5kQ Vs 50V 60Hz C1 1 F Solve for the total current in the circuit Select one O a 13 71 mA O b 9 7 mA O c 18 8 mA O d 20 mA Oe None of the above

A rectangle is inscribed in the parabola y x 3 as shown with its base on the x axis L 3 A x 2 4F Write the area A of the rectangle as a function of x A x 19 X Open A x 1 x y 4H y 2 Find the domain of the function Enter your answer using interval notation 0 00 x Tutorial 2 Find the objective function for the given calculus problem Give the domain of the objective function but do not actually attempt to solve the problem Domain Enter your answer using interval notation X 1 An open rectangular box is to be constructed with a square base and a volume of 96 000 cm See the figure below cm 2 3 a Find the dimensions of the open box that require the least amount of material Let A represent the surface area of the open box Enter your answer in terms of x 384000 X cm X b If the rectangular box in part a is closed find the dimensions that require the least amount of material Let A represent the surface area of the closed box terms of x 2x 384000 1 UN DEF 0 0 DINE

are placed on top of each other on a horizontal table If the mass of each coin is 10 g and acceleration due to gravity is 10 ms 2 what is the magnitude and direction of the force on the 7th coin counted from the bottom due to all the coins above it 1 0 3 N downwards 3 0 7 N downwards 2 0 3 N upwards 4 0 7 N upwards

Two force are acting on a particle as shown in the figure A third force is applied on the particle such that net force on the particle becomes along positive x axis What is the magnitude of third force in newton y 10 N 53 12 N X

The spectral emissive power Ex for a body at temperature T is plotted against the wavelength and area under the curve is found to be A At a different temperature T the area is 2 found to be 9A Then dE d 2 is T T

A 1 5 kg block is initially at rest on a horizontal frictionless surface when a horizontal force in the positive direction of x axis is applied to the block The force is given byF 4 x N where x is in metre and the initial position of the block is x 0 The maximum kinetic energy of the block between x 0 and x 2 0 m is A 2 33 J C 5 33 J B 6 87 J D 6 67 J

3 45 4 60 Three blocks of masses 4 kg 2 kg and I ke ram nee respectively are in contact on a frictionless table as shown in the figure If a force of 14 N is applied on the 4 kg block the contact force between the 4 kg and the 2 kg block will be 14 N 1 2 N 721 ON 4 kg 2 kg 1 kg 2 6 N 14N

A thin bar magnet is placed in a uniform magnetic field and is aligned with the field The needle is now rotated by an angle of 45 and the work done is W The torque on the magnetic needle at this position is 1 zero W 5 2 3 W 2 4 zw

A block of mass 2 kg is placed on rough horizontal surface and pulled with a horizontal constant force F that its velocity remains 2 cm s constant If coefficient of friction between surface and block is 0 2 then value of work done in J by F in 10 sec is

A uniform chain of length I is placed on a smooth horizontal table such that half of its length hangsover one edge It is released from rest the velocity with which it leaves the table is A 3gl B C 3gl 2gl V 3

A particle of mass m and velocity v collides oblique elastically with a stationary particle of mass m The angle between the velocity vectors of the two particles after the collision is in degree

4 CRANE A simple crane is shown in the below diagram consisted of light rods with length 1 m and 2 m The end of the crane is supporting a 5 kN object Point B is known as a pin It is attached to the main body and can exert both a vertical and horizontal force Point A is known as a roller and can only exert vertical forces Rods can only be in pure compression or pure tension 5 KN C D In kN what is the force experienced by the rod CD Express a positive number if the member is in

Two coils 1 2 are placed as shown in figure Coefficient of mutual induction between 1 2 is M 6 H Find induced emf induced current in coil 2 R of coil 2 is 40 i 4t Coil Coil 2

ning f jing m T2 2mg 2 ma 3 ma ig System shown in figure is in equilibrium and at rest The spring and string are massless Now the string s cut The acceleration of mass 2m and m just fter the string is cut will be 1 g 2 upwards g downwards g upwards g 2 downwards g upwards 2g downwards 2 3

A satellite of earth is to be launched from earth surface in to an orbit of radius 2R Then the additional kinetic energy to be provided to the satellite is mass of satellite is m and mass of earth is M A B 3GMm 4R GMm 4R

2 21 A ball falls from a height of 1 m on a ground and it loses half its kinetic energy when it hits the ground What would be the total distance covered by the ball after sufficiently long time

A bullet fired at an angle of 60 with the vertical hits the ground at a distance of 2 km Calculate the distance at which the bullet will hit the ground when fired at an angle of 45 assuming the speed to be the same Ans 2 31 km

A car is moving towards an approaching bike Bike is moving with velocity 30 m s Frequency of horn sounded by car is 100 Hz while it is observed by bike rider as 120 Hz The actual duration of horn is 6 sec Find the time the bike rider hears it in seconds Take velocity of sound in air as 330 m s 5

Consider the following two statements about Oersted s experiments Statement P The magnetic field due to a straight current carrying conductor is in the form of circular loops around it Statement Q The magnetic field due to a current carrying conductor is weak at near points from the conductor compared to the far points Both P and Q are true Both P and Q are false 1 point P is true but Q is false OP is false but Q is true

P PA P2 P Po 1 Tension in the string connecting P P and P is zero 2 Tension in the string connecting P P and P is mg 3 3 Tensions in all the three strings are same and equal to zero 4 Acceleration of P is g downwards and that of P is g upwards

A cylindrical parallel beam of light of radius r falls on a thin convex lens of focal length 40 cm and then on a concave lens of focal length 10 cm as shown Area illuminated by beam on the screen is 1 3 f 40 cm f 10 cm 9 r 16 r 30 cm 2 4 50 cm 2 r 4 3 r 16 Screen

27 A block of mass m 2 kg is moving with velocity v towards a massless unstretched spring of force constant k 10 N m The coefficient of friction between the block 1 and the ground is Find the maximum value of v 5 so that after pressing the spring the block does not return back but stops there permanently 1 6 m s m K 1 mooo 2 12 m s

In sonometer experiment the bridges are separated by a fixed distance The wire which is slightly elastic emits a tone of frequency n when held by tension T If the tension is increased to 4T the tone emitted by the wire will be of frequency MH CET 2015 A n B 2n C slightly greater than 2n D slightly less than 2n

y A sin kx ot iw mulas Tin b y2 A sin kx wt p and y3 A sin kx wt 20 are superimposed so that y y2 y3 0 at all positions Then the value of is forfavods 2 3 a T b lot c 3 drgnist side ibs d 4 3 TC 2

A compass needle is placed above a straight conducting wire If the current passes through the conducting wire from South to North Then the deflection of the compass is O Towards West O O O Towards East Keeps oscillating in East West direction No deflection 1 poi